The use of volatile flavoring oils and perfumes in such applications as foods and cosmetics is often greatly hampered by the rapid evaporation and loss of the volatile component. The losses detract from the desirability as well as from the utility of the products concerned.
Techniques used to overcome this problem generally involve the preparation of solid compositions containing the volatile ingredient entrapped therein. These compositions may be prepared by mixing the volatile oil with a suitable absorbent base. In another method, the volatile materials are dispersed by mixing and emulsification with solutions of various protective colloids, such as natural gums, e.g., water-dispersible gum arabic.
The encapsulated particles, in these applications, have been characterized by their extreme water solubility. This property has been considered essential in order to make possible the ready release of the entrapped flavor as the encapsulated particles are moistened or dispersed in water.
U.S. Pat. Nos. 3,091,567, and 2,661,349, and 2,613,206 disclose starch acid-ester encapsulating agents which are dispersible in water and form a water repellant film upon drying. The starches disclosed in these patents are modified by acid-treatment to produce high fluidity and thin-boiling characteristics. The acid treatment process is time consuming and frequently results in damage to storage tanks.
It is an object of this invention to produce encapsulating agents which are water-dispersible and form films with the proper hydrophobic-hydrophilic balance upon drying to provide a gradual or controlled release of the substance entrapped by the encapsulating agent.
Another object of the present invention is to make a thin-boiling starch by controlled modification of the starch by enzyme treatment. Yet another object of the present invention is to produce a spray-dried enzyme converted starch reaction product which may be used in the form of an aqueous dispersion with an oil to form a stable emulsion. The oil-in-water emulsion may be dried and later reconstituted to provide a stable emulsion.
When resuspended in water, the spray-dried product causes a cloud effect. The cloud effect is an opaqueness in the fluid which is used in certain types of drinks made from dried flavorings. Gum arabic also has this cloud effect.